1. Technical Field
The present invention relates to a container valve and more specifically to a technique for enabling the container valve to open and close smoothly over a prolonged period of time.
2. Explanation of Earlier Technology
A closure member is inserted into a valve chamber hermetically partitioned by a diaphragm. The closure member is brought into closing contact with a valve seat through the diaphragm with a screw thrust of a spindle arranged outside the diaphragm. There is a conventional container valve which separates the closure member from the valve seat with an urging force of a spring for valve opening attached within the valve chamber, contrary to the above construction.
A certain kind of fluid to be accommodated in a container, for example, such as specific soil fumigant, comes to be like tar upon contact with the air and resides and solidifies at that tar state in the container.
When the specific fluid of this kind is used in the conventional diaphragm-type container valve, as the container valve repeatedly opens and closes, the residue is going to stickily adhere to the spring for valve opening attached within the valve chamber. This results in being unable to extend and contract the spring for valve opening. Accordingly, there was a likelihood that the container valve could not open nor close at an earlier time after having commenced to use it.
The present invention has an object to provide a container valve which can smoothly open and close over a prolonged period of time.
In order to accomplish the above-mentioned object, the present invention has constructed a container valve in the following manner, for example, as shown in FIGS. 1 to 3.
The container valve comprises a housing 3 within which a fluid inlet 5 communicates with a fluid outlet 7 via a valve seat 9 and a valve chamber 10. A closure member 15 is inserted into the valve chamber 10, which communicates with a guide hole 14. Inserted into the guide hole 14 is a transmission member 17, through which the closure member 15 is connected to an operation means 18. The operation means 18 enables the closure member 15 to operate for opening and closing with respect to the valve seat 9. An annular scraper 21 is attached between the closure member 15 and a peripheral wall of the valve chamber 10. The annular scraper 21 has an inner peripheral surface brought into contact with an outer peripheral surface of the closure member 15. A sealing member 23 is attached in at least any one of spaces defined between the closure member 15 and the guide hole 14, between the closure member 15 and the inner peripheral surface of the scraper 21, between the transmission member 17 and the guide hole 14, and between the transmission member 17 and the inner peripheral surface of the scraper 21.
The present invention as shown in FIGS. 1 to 3 produces the following function and effect.
When using fluid which comes to be like tar upon contact with the air and resides and solidifies, for example, such as specific soil fumigant, in a container valve, the residue adheres to an outer peripheral surface of a closure member of the container valve.
However, on switching over the closure member from a closed position to an opened position and switching over it from the opened position to the closed position by the operation means, the annular scraper scrapes off the residue adhered to the outer peripheral surface of the closure member. This prevents the residue from invading a space between the closure member and the guide hole to result in the possibility of smoothly opening and closing the closure member for a long period of time.
Besides, a sealing member is attached between at least one of the guide hole and the inner peripheral surface of the scraper, and at least one of the closure member and the transmission member. The valve chamber can keep its hermetical state by the sealing member. This can surely inhibit the leak-out of the fluid within the valve chamber.
Concretely, the sealing member can be attached between the closure member and the inner peripheral surface of the scraper and/or between the transmission member and the guide hole. Further, in the case where the closure member is inserted throughout the guide hole and the valve chamber, for example, as shown in FIG. 1, it can be also attached between the closure member and the guide hole. Besides, in the event that the transmission member is inserted throughout the guide hole and the valve chamber, the sealing member can be attached between the transmission member and the scraper.
Additionally, the sealing member will be able to inhibit the leak-out of the fluid within the valve chamber more assuredly if it is attached at a plurality of portions. For instance, it is possible to prevent the fluid from invading the space defined between the guide hole and the transmission member and damaging the movement of the transmission member and so on for a prolonged period of time.
The annular scraper is generally fixed to a peripheral wall of the valve chamber. Concretely, for example, as shown in FIGS. 1 to 3, a cap member 13 provided with the guide hole 14 is fixed to the housing 3 in screw-thread engagement. The annular scraper is held between the cap member and the peripheral wall of the valve chamber.
Further, in order to accomplish the above object, another embodiment of the invention has constructed a container valve in the following manner, for example, as shown in FIG. 4.
The container valve comprises a housing 3 within which a fluid inlet 5 communicates with a fluid outlet 7 via a valve seat 9 and a valve chamber 10. A closure member 15 is inserted into the valve chamber 10 and is connected to an operation means 18 through a transmission member 17. The operation means 18 enables the closure member 15 to operate for opening and closing straightly with respect to the valve seat 9. An annular diaphragm 41 is provided so as to cover the valve chamber 10. The diaphragm 41 has an outer peripheral edge portion hermetically fixed to a peripheral wall of the valve chamber 10 and has an inner peripheral edge portion hermetically fixed to the closure member 15.
According to this embodiment of the invention, the operation means can move the closure member for opening through the transmission member. Therefore, differently from the above-mentioned conventional structure, it dispenses with the necessity of attaching the spring for valve opening within the valve chamber. This reduces the number of parts to be attached within the valve chamber and also simplifies the attaching structure within the valve chamber. As a result, it can largely decrease damage caused by the residue of the specific fluid to thereby lengthen the term during which the contained valve can smoothly open and close.
Further, in this embodiment of the invention, if the annular diaphragm has a face on the valve chamber side, which is formed from synthetic resin of self-lubrication type, the residue of the specific fluid hardly adheres to the diaphragm. This enables the container valve to smoothly open and close over a far longer period of time.
In addition, in order to accomplish the above object, yet another embodiment of the invention has constructed a container valve in the following manner, for example, as shown in FIG. 5.
According to this embodiment, the invention, there is provided the slide member formed from synthetic resin of self-lubrication type between the closure member and the peripheral wall of the valve chamber. Thus it is possible to easily scrape from the slide member, the residue of the specific fluid which has entered a space between the slide member and the closure member. This results in greatly reducing the disadvantages caused by the residue of the specific fluid, such as damaging the movement of the closure member, to lengthen the term during which the container valve can open and close smoothly.
The slide member may be formed in the shape of a cylinder fixed to the valve chamber, for example, as shown in FIG. 5. Alternatively, the peripheral wall of the valve chamber may have an inner surface lined or coated with synthetic resin of self-lubrication type and/or the closure member may have an outer peripheral surface lined or coated with synthetic resin of self-lubrication type. The thus formed coating layer may compose the slide member.